This invention pertains to a cooling system for a thin section continuous casting machine of advanced design which will provide the initial forming stage in a process route which leads to cold rolled strip and sheet steel.
In a thin section continuous caster operating at a relatively high casting speed, the moving surface which receives the molten steel is subjected to an extremely high heat flux. For purposes of example, one given prototype caster which may have 0.05 inch (0.13 cm) thick steel cast at a speed of 25 ft./sec. (7.6 m/sec.) on a drum which is about 7 ft. (2.13 m) in diameter, and with a desired puddle length of 3 ft. (0.91 m), the average heat flux over the solidification zone on the outside surface of the caster drum is 6.2.times.10.sup.6 BTU/ft..sup.2 -hour (1.98 kW/cm.sup.2). A comparable heat flux is experienced in the zone where the sheet is sub-cooled below the solidification temperature prior to leaving the caster drum. By way of reference, this heat flux is about an order of magnitude higher than the maximum heat flux existing in the core of a pressurized water-cooled nuclear reactor, and is comparable with heat fluxes experienced at the surfaces of chemical rocket nozzles. Accordingly, a cooling system using extraordinary cooling methods must be employed in order to prevent deformation of the caster drum.
It is the aim of this invention to provide such a cooling system which is adequate to accommodate the heat flux for a caster such as the prototype to be described herein, as well as other parametrically similar casters.